Police in Michigan are Christopher Caldwelllooking for an auto plant employee who they say struck a group of picketing auto workers with their vehicle outside a plant Tuesday afternoon.

Chief Matthew Bade of the Metro Police Authority of Genesee County told ABC affiliate WJRT that the employee was leaving the Flint Processing Center on Bristol Road in Swartz Creek when he struck the crowd that was picketing around 4 p.m.

The picketers were allegedly blocking a driveway to the plant as the employee was exiting the facility, Bade said.

At least five people were injured in the incident with minor injuries, according to Bade. No one was hospitalized.

The driver wasn't immediately identified or found, police said.

Jack Crawley, a spokesman for General Motors, which operates the plant, said in a statement, "Plant leadership is working closely with local authorities to investigate and understand what happened."